NACHI NJ204 NJ Cylindrical Roller Bearing 20x47x14 mm
Available
This NACHI range covers 19 single row cylindrical roller bearings in NJ configuration (two flanges on the outer ring and one flange on the inner ring), with Normal (CN) radial internal clearance. Bores run from 20 to 70 mm (200 and 300 series; outer diameters 47 to 150 mm, widths 14 to 35 mm). Select the size from the drop-down: each size has its own bearing number, load ratings and limiting speeds in the Model Details.
The inner ring and roller set can be separated from the outer ring. It takes axial load in one direction and locates the shaft in that direction only. Cylindrical roller bearings have line contact between rollers and raceways, which gives a high radial load capacity for the size.
Where this product is used
- Electric motors and generators
- Gearboxes and industrial transmissions
- Pumps, fans and compressors
- Machine tools and general industrial machinery
- Conveyor drives and other heavy rotating equipment
Features
- NJ configuration, with two flanges on the outer ring and one flange on the inner ring. The inner ring and roller set can be separated from the outer ring.
- Takes axial load in one direction and locates the shaft in that direction only. Axial load is carried by sliding contact between roller ends and flanges, so the allowable axial load is limited
- Normal (CN) radial internal clearance: 20 to 45 µm on a 20 mm bore up to 40 to 75 µm on a 70 mm bore
- Basic dynamic load rating Cr 15.4 to 158 kN and basic static load rating Cor 12.7 to 220 kN across the range; load ratings, speeds and dimensions for every size come from the manufacturer’s catalogue
Key specifications
| Specification | Detail |
|---|---|
| Type | Single row cylindrical roller bearing, NJ configuration |
| Bearing numbers | 19 (200 and 300 series) |
| Bore d | 20 to 70 mm |
| Outer diameter D | 47 to 150 mm |
| Width B | 14 to 35 mm |
| Configuration | Outer ring with two flanges, inner ring with one flange |
| Axial location | Takes axial load in one direction and locates the shaft in that direction only |
| Radial internal clearance | Normal (CN) (see Model Details for µm range per size) |
| Standard cage for these sizes (catalogue) | Pressed steel |
| Basic dynamic load rating Cr | 15.4 to 158 kN |
| Basic static load rating Cor | 12.7 to 220 kN |
| Brand | NACHI |
Available sizes
Show all 19 sizes with load ratings and speeds
| Model | Size d x D x B (mm) | Cr (kN) | Cor (kN) | Grease (rpm) | Oil (rpm) |
|---|---|---|---|---|---|
| NJ204 | 20 x 47 x 14 | 15.4 | 12.7 | 15,000 | 18,000 |
| NJ205 | 25 x 52 x 15 | 17.7 | 15.7 | 13,000 | 16,000 |
| NJ305 | 25 x 62 x 17 | 29.3 | 25.2 | 10,000 | 13,000 |
| NJ206 | 30 x 62 x 16 | 23.5 | 21.5 | 11,000 | 13,000 |
| NJ306 | 30 x 72 x 19 | 38.5 | 35 | 8,500 | 11,000 |
| NJ207 | 35 x 72 x 17 | 33.5 | 31.5 | 9,500 | 11,000 |
| NJ307 | 35 x 80 x 21 | 49.5 | 47 | 8,000 | 9,500 |
| NJ308 | 40 x 90 x 23 | 58.5 | 57 | 6,700 | 8,500 |
| NJ309 | 45 x 100 x 25 | 78.5 | 77.5 | 6,300 | 7,500 |
| NJ210 | 50 x 90 x 20 | 48 | 51 | 7,100 | 8,500 |
| NJ310 | 50 x 110 x 27 | 87 | 86 | 5,600 | 6,700 |
| NJ211 | 55 x 100 x 21 | 58 | 62.5 | 6,300 | 7,500 |
| NJ311 | 55 x 120 x 29 | 111 | 111 | 5,000 | 6,300 |
| NJ212 | 60 x 110 x 22 | 68.5 | 75 | 6,000 | 7,100 |
| NJ312 | 60 x 130 x 31 | 124 | 126 | 4,800 | 5,600 |
| NJ213 | 65 x 120 x 23 | 84 | 94.5 | 5,300 | 6,300 |
| NJ313 | 65 x 140 x 33 | 135 | 139 | 4,500 | 5,300 |
| NJ214 | 70 x 125 x 24 | 83.5 | 95 | 5,000 | 6,300 |
| NJ314 | 70 x 150 x 35 | 158 | 220 | 4,000 | 5,000 |
Limiting speeds are the catalogue table values for machined-cage bearings; for a pressed steel cage (the catalogue standard cage for these sizes) multiply by 0.8.
Selecting the right option
The NJ configuration has two flanges on the outer ring and one flange on the inner ring. It takes radial load plus axial load in one direction, and so locates the shaft in that direction only. Axial load is carried by sliding contact between roller ends and flanges, so the allowable axial load is limited: for heavy or continuous axial load, send AIMS the application details first.
These are Normal (CN) clearance bearings. If the inner ring will run hotter than the outer ring, the shaft deflects a lot, or the fits are tight, the C3 versions in the Related products section may suit better.
Both 200 and 300 series bearings are listed. For the same bore the 300 series has a larger outer diameter and width and a higher load rating than the 200 series, so choose on the housing space you have and the load to be carried.
Fitting and use
Check the load and speed against the catalogue figures before ordering and apply a suitable safety factor. Cylindrical roller bearings are mainly for radial load: any axial load must be well within what the flanges can carry by sliding contact, and the limit depends on lubrication and speed as well as the bearing.
The catalogue limiting speeds are for machined-cage bearings; for a pressed steel cage multiply them by 0.8. Pressed steel is the catalogue standard cage for these sizes, so the Model Details show both figures for each size.
Where axial load is applied, keep enough radial load on the bearing, supply plenty of lubricant between the roller ends and flanges, use a lubricant with good film strength, mount the bearing accurately, allow a running-in period and keep the radial clearance small.
These bearings are open: the housing arrangement has to supply and hold the lubricant and keep contamination out. Fit the rings with the housing and shaft tolerances recommended for your application, and keep the shaft and housing seats clean and square.
If you are replacing a bearing, check the full number stamped on it, including any letters after the digits, and send AIMS the number or the dimensions if you are not sure.
Related products
More sizes in the same configuration: NACHI NJ C3 cylindrical roller bearings (12 sizes) and NACHI NJ EG C3 cylindrical roller bearings (2 sizes). Other configurations: NACHI NU cylindrical roller bearings (23 sizes) and NACHI N cylindrical roller bearings (25 sizes). For combined radial and axial loads on one bearing, see the NACHI tapered roller bearings (metric series).
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20 x 47 x 14mm bearing
Model Number: NJ204/NACHI
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25 x 62 x 17mm bearing
Model Number: NJ305/NACHI
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25 x 52 x 15mm bearing
Model Number: NJ205/NACHI
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30 x 72 x 19mm bearing
Model Number: NJ306/NACHI
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30 x 62 x 16mm bearing
Model Number: NJ206/NACHI
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35 x 80 x 21mm bearing
Model Number: NJ307/NACHI
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35 x 72 x 17mm bearing
Model Number: NJ207/NACHI
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40 x 90 x 23mm bearing
Model Number: NJ308/NACHI
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45 x 100 x 25mm bearing
Model Number: NJ309/NACHI
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50 x 90 x 20mm bearing
Model Number: NJ210/NACHI
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50 x 110 x 27mm bearing
Model Number: NJ310/NACHI
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55 x 120 x 29mm bearing
Model Number: NJ311/NACHI
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55 x 100 x 21mm bearing
Model Number: NJ211/NACHI
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60 x 130 x 31mm bearing
Model Number: NJ312/NACHI
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60 x 110 x 22mm bearing
Model Number: NJ212/NACHI
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65 x 140 x 33mm bearing
Model Number: NJ313/NACHI
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65 x 120 x 23mm bearing
Model Number: NJ213/NACHI
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70 x 150 x 35mm bearing
Model Number: NJ314/NACHI
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70 x 125 x 24mm bearing
Model Number: NJ214/NACHI
